Reduced EBP50 expression or mis-localization of the EBP50 protein is associated with the malignant progression of esophageal squamous cell carcinoma.

PURPOSE The aim of this study was to examine the significance of EBP50 (ezrin-radixin-moesin binding phosphoprotein 50) expression in esophageal squamous cell carcinoma (ESCC). MATERIALS AND METHODS Real-time PCR (qRT-PCR), western blotting, and immunohistochemical staining were performed to detect EBP50 expression in pairs of ESCCs and matched non-tumor tissues, and the relationships between EBP50 expression and other clinical factors in ESCC were analyzed. An iRNA targeting EBP50 was transfected into EC9706 cells. MTT and plate colony assays were performed to assess the effects of EBP50 down-regulation on cell growth, and flow cytometry was used to evaluate the influence of inhibiting EBP50 on cell cycle progression. RESULTS The real-time PCR (qRT-PCR), western blotting, and immunohistochemical staining results showed that EBP50 expression was significantly lower in ESCCs compared to matched non-tumor tissues. In addition, decreased EBP50 expression correlated with differentiation, T stage, lymph node (LN) metastasis, and poor prognosis in patients with ESCC. The down-regulation of EBP50 may significantly promote the growth and proliferation of EC9706 cells while accelerating cell cycle progression from the G1to S phase. CONCLUSIONS EBP50 expression was decreased in ESCC, indicating that EBP50 might play a significant role in the malignant progression of ESCC and be a prognostic marker for patients with ESCC.